The present invention is directed generally to portable containers useful for the shipping and/or storage of goods and materials and for field housing applications, and more particularly to such containers which are foldable and which are provided with an integral mechanical mechanism for effecting the folding and unfolding of the containers without the assistance of external lifting equipment.
The efficiency and costs associated with the moving, shipping and/or storage of various goods and materials has been greatly improved through the use portable containers that can be easily transported to different locations by a suitable carrier such as a truck, rail, or ship. These portable containers are provided in a wide range of sizes varying from relatively small volume containers that are particularly suitable for storage and moving applications and usually transported by truck to larger volume containers suitable for transport of goods and materials by rail or shipping lines.
One shortcoming found to be present with previously known portable containers is that these containers whether empty or filled require the same space for transportation and storage purposes. This problem has been addressed by utilizing foldable containers which can be shipped and stored in a folded state and then unfolded for receiving storable goods and subsequent storage or shipping and storage of the loaded containers. Such a foldable container which when folded occupies a significantly smaller volume than when in an unfolded state has been provided by Peter S. Warhurst et al as shown and described in United States Patent Application Publication, No. US 2007/0108204 A1, published May 17, 2007. Another such foldable container is described by Ono et al in U.S. Pat. No. 4,684,034, issued Aug. 4, 1987. The publication and the patent are each directed to foldable portable containers having foldable end walls pivotally attached to either the floor or the roof and sidewalls pivotally attached to both the roof and floor folded in the middle to fold the container. In a container folding operation, the end walls are initially pivotally folded and then the side walls with the attached roof are folded inwardly to provide a folded container of a significantly reduced volume. The empty containers are unfolded by simply reversing the folding operation. Inasmuch as the side walls and the attached roof of such known portable containers are cumbersome and relatively heavy for manually handling, a lifting mechanism such as provided by a fork lift or crane is necessary to support, lower and lift the roof and side walls during both the container folding and unfolding operations.